CN110723721A - Method for preparing silicon-carbon negative electrode material of lithium battery, negative electrode material and lithium battery - Google Patents

Method for preparing silicon-carbon negative electrode material of lithium battery, negative electrode material and lithium battery Download PDF

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CN110723721A
CN110723721A CN201911025032.6A CN201911025032A CN110723721A CN 110723721 A CN110723721 A CN 110723721A CN 201911025032 A CN201911025032 A CN 201911025032A CN 110723721 A CN110723721 A CN 110723721A
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silicon
mixture
hours
ball milling
lithium battery
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袁树兵
冯苏宁
刘芳
李辉
卢勇
顾华清
周勇岐
李婷
毕文君
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Liyang Zichen New Materials Technology Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/02—Silicon
    • C01B33/021—Preparation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/03—Particle morphology depicted by an image obtained by SEM
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The embodiment of the invention relates to a method for preparing a silicon-carbon negative electrode material of a lithium battery, the negative electrode material and the lithium battery, wherein the method comprises the following steps: mixing nano silicon and graphite with a median particle size of 3-15 um according to a mass ratio, and carrying out ball milling for 1-3 hours; mixing asphalt and tetrahydrofuran according to the mass ratio of 3: 50-3: 40 to form an asphalt mixed solution, and adding the asphalt mixed solution into a ball milling tank for ball milling to form a first mixture; the mass ratio of the asphalt mixed solution to the silicon to the graphite is 20:5: 10-40: 10: 30; adding carboxymethyl cellulose CMC accounting for 1-5% of the mass of the silicon, and mixing and ball-milling for 3-5 hours to obtain a second mixture; drying in an oven for 8-12 hours to completely volatilize the organic solvent in the second mixture, and crushing and sieving; and (3) placing the sieved substance in a box-type carbonization furnace, introducing nitrogen at the flow rate of 50-80L/h, heating after 2.5-5 hours, heating for 4-6 hours, preserving the heat at 900-1000 ℃ for 2-4 hours, and naturally cooling to obtain the lithium ion battery silicon-carbon cathode material.

Description

Method for preparing silicon-carbon negative electrode material of lithium battery, negative electrode material and lithium battery
Technical Field
The invention relates to the technical field of battery materials, in particular to a method for preparing a silicon-carbon negative electrode material of a lithium battery, the negative electrode material and the lithium battery.
Background
With the rapid popularization of lithium ion batteries in the fields of electric vehicles and energy storage, the requirements for high power density and high energy density are increasingly prominent.
At present, the commercialized negative electrode material mainly takes graphite as a main material, has low theoretical capacity (372mAh/g), is higher than the theoretical capacity (4200mAh/g) of silicon, and has the advantages of good safety performance, low discharge voltage and the like. However, silicon is accompanied by a large volume change during lithium deintercalation, and a thick SEI film is formed during lithium intercalation, which causes disadvantages of poor cycle performance, low first-pass efficiency, and the like.
How to improve the cycle performance of silicon-carbon anode materials and improve the first effect thereof has become the focus of research in the industry.
Disclosure of Invention
The invention aims to provide a method for preparing a lithium battery silicon-carbon negative electrode material, the negative electrode material and a lithium battery.
In order to achieve the above object, in a first aspect, the present invention provides a method for preparing a silicon-carbon anode material for a lithium battery, the method comprising:
mixing nano-silicon and graphite with a median particle size of 3-15 um according to a mass ratio of 5: 10-10: 30, and putting the mixture into a ball milling tank for ball milling for 1-3 hours;
mixing asphalt and tetrahydrofuran according to the mass ratio of 3: 50-3: 40 to form an asphalt mixed solution, and adding the asphalt mixed solution into a ball milling tank for ball milling to form a first mixture; in the first mixture, the mass ratio of the asphalt mixed solution to the silicon to the graphite is 20:5: 10-40: 10: 30;
adding carboxymethyl cellulose (CMC) accounting for 1-5% of the mass of silicon into the first mixture, and mixing and ball-milling for 3-5 hours to obtain a second mixture;
drying the second mixture in an oven for 8-12 hours to ensure that all organic solvents in the second mixture are volatilized to obtain a third mixture;
crushing and screening the third mixture;
placing the sieved substances in a box-type carbonization furnace, and introducing nitrogen at the flow rate of 50-80L/h; and (3) heating up 2.5-5 hours after nitrogen is introduced, heating up to 900-1000 ℃ after 4-6 hours, preserving heat for 2-4 hours, and naturally cooling to obtain the silicon-carbon cathode material of the lithium ion battery.
Preferably, the ball milling tank adopts an agate ball milling tank, the volume of the ball milling tank is 100mL, zirconium dioxide zirconium beads with the purity of 95% are used in the ball milling tank, and the volume of the zirconium beads in the ball milling tank is 1/3.
Preferably, the median particle size of the graphite is 6-12 um.
Further preferably, the median particle diameter of the graphite is 8-11 um.
Preferably, the temperature of the oven is 60-80 ℃.
Preferably, the mixing of the pitch and tetrahydrofuran is performed in a beaker and stirred with a glass stir bar.
Preferably, the sieving is specifically a 300 mesh sieve.
In a second aspect, the embodiment of the present invention provides a lithium battery silicon carbon negative electrode material prepared by the method in the first aspect.
In a third aspect, the embodiment of the present invention provides a lithium battery including the lithium battery silicon carbon negative electrode material described in the second aspect.
According to the method for preparing the silicon-carbon negative electrode material of the lithium battery, the dispersibility of silicon and graphite is changed by adding carboxymethyl cellulose (CMC), nano silicon and graphite are uniformly mixed by ball milling, the nano silicon is uniformly dispersed on a graphite carrier, pitch dissolved by tetrahydrofuran is effectively coated on the surfaces of the nano silicon and the graphite by ball milling, and then carbon generated by cracking the pitch is coated on the surfaces of nano silicon particles by high-temperature carbonization and becomes effective connection of the nano silicon and the graphite carrier, so that the performance of the material is improved. The silicon-carbon cathode material prepared by the method has the advantages of high gram capacity and high first-cycle efficiency.
Drawings
FIG. 1 is a flow chart of a method for preparing a silicon-carbon negative electrode material of a lithium battery according to an embodiment of the present invention;
fig. 2 is an X-ray diffraction (XRD) pattern of the silicon-carbon negative electrode material provided by the embodiment of the present invention;
fig. 3 is a Scanning Electron Microscope (SEM) image of a silicon carbon negative electrode material provided in an embodiment of the present invention;
fig. 4 is a test curve of electrochemical performance of a half cell made of the silicon-carbon negative electrode material provided in example 1 of the present invention.
Detailed Description
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
The embodiment provides a method for preparing a silicon-carbon negative electrode material of a lithium battery, which is used for preparing the negative electrode material of the lithium battery. Fig. 1 is a flow chart of a method for preparing a silicon-carbon negative electrode material of a lithium battery according to an embodiment of the present invention, and the following describes an embodiment of the preparation method according to fig. 1. The preparation method mainly comprises the following steps:
110, mixing nano silicon and graphite with a median particle size of 3-15 um according to a mass ratio of 5: 10-10: 30, and putting the mixture into a ball milling tank for ball milling for 1-3 hours;
specifically, the ball milling tank used in this step and the following steps may specifically adopt an agate ball milling tank with a volume of 100mL, the ball milling tank uses zirconium dioxide and zirconium beads with a purity of 95%, and the amount of the zirconium beads accounts for 1/3 of the volume of the ball milling tank.
In other embodiments, ball milling may also be accomplished using a ball mill, such as a planetary ball mill, instead of a ball milling jar.
Preferably, the median particle diameter of the graphite is 6-12 um, and more preferably 8-11 um.
Step 120, mixing asphalt and tetrahydrofuran according to a mass ratio of 3: 50-3: 40 to form an asphalt mixed solution, and adding the asphalt mixed solution into a ball milling tank for ball milling to form a first mixture;
specifically, the mixing of the pitch and tetrahydrofuran was performed in a beaker and stirred with a glass stir bar. In the obtained first mixture, the mass ratio of the asphalt mixed solution to the silicon to the graphite is 20:5: 10-40: 10: 30.
Step 130, adding carboxymethyl cellulose (CMC) accounting for 1-5% of the mass of silicon into the first mixture, and mixing and ball-milling for 3-5 hours to obtain a second mixture;
step 140, drying the second mixture in an oven for 8-12 hours to completely volatilize the organic solvent in the second mixture to obtain a third mixture;
specifically, the temperature of the oven is preferably set to 60 ℃ to 80 ℃.
Step 150, crushing and sieving the third mixture;
specifically, the sieving is 300 mesh sieve.
160, placing the sieved substances in a box-type carbonization furnace, and introducing nitrogen at the flow rate of 50-80L/h;
and 170, heating up after 2.5-5 hours of introducing nitrogen, keeping the temperature at 900-1000 ℃ after heating up for 4-6 hours, preserving the temperature for 2-4 hours, and naturally cooling to obtain the silicon-carbon cathode material of the lithium ion battery.
According to the method for preparing the silicon-carbon negative electrode material of the lithium battery, the dispersibility of silicon and graphite is changed by adding carboxymethyl cellulose (CMC), nano silicon and graphite are uniformly mixed by ball milling, the nano silicon is uniformly dispersed on a graphite carrier, pitch dissolved by tetrahydrofuran is effectively coated on the surfaces of the nano silicon and the graphite by ball milling, and then carbon generated by cracking the pitch is coated on the surfaces of nano silicon particles by high-temperature carbonization and becomes effective connection of the nano silicon and the graphite carrier, so that the performance of the material is improved. The silicon-carbon cathode material prepared by the method has the advantages of high gram capacity and high first-cycle efficiency.
The following specific examples are provided to illustrate the process and performance of the present invention for preparing silicon carbon negative electrode material for lithium battery.
Example 1
The embodiment provides a preparation method of a silicon-carbon negative electrode material of a lithium ion battery, which specifically comprises the following steps:
a: weighing 5g of nano silicon with the median particle size of 100nm and 10g of artificial graphite, placing the nano silicon and the artificial graphite in a 500mL beaker, stirring and mixing the mixture for 10min, and placing the mixture in a ball milling tank for ball milling for 2 hours at the rotating speed of 300 r/min;
b: adding 1.5g of asphalt into 25g of tetrahydrofuran and mixing;
c: adding the mixed solution obtained in the step B into the ball milling tank in the step A;
d: adding 0.05g of CMC to the mixture obtained in step C and ball milling the mixture for 3 hours;
e: putting the mixture obtained in the step D in an oven at the temperature of 80 ℃ for drying for 12 hours until the organic solvent is completely volatilized;
f: crushing the mixture obtained in the step E and sieving the crushed mixture with a 300-mesh sieve;
g: and F, placing the mixture obtained in the step F in a box-type carbonization furnace, introducing nitrogen as protective gas at the flow rate of 80L/h for 2.5 hours, then starting to heat up at the heating rate of 3 ℃/min to 1000 ℃, preserving heat for 4 hours, and naturally cooling to obtain the silicon-carbon negative electrode material for the lithium ion battery.
Fig. 2 is an X-ray diffraction pattern (XRD) of the silicon carbon negative electrode material prepared in example 1 of the present invention, and the XRD diffraction peaks show that the silicon carbon negative electrode material has diffraction peaks of silicon and graphite, indicating that no SiC is generated.
Fig. 3 is a Scanning Electron Microscope (SEM) of the silicon-carbon negative electrode material prepared in example 1 of the present invention, and it can be seen from the SEM that the nano-silicon is effectively dispersed on the graphite carrier, and the surface of the nano-silicon is uniformly coated with a layer of amorphous carbon formed by pyrolysis of pitch.
Fig. 4 is a charge-discharge curve at a constant current of 0.1C after a button half cell made of the silicon-carbon negative electrode material prepared in example 1 of the present invention, where there are 1 narrow discharge platforms around 0.3V on the discharge curve, which is caused by the formation of a Solid Electrolyte Interface (SEI) film; below 0.1V there are 1 wider discharge plateau, which is the formation of silicon-lithium alloy during the primary discharge; the charging platform is between 0.3V and 0.6V.
And (3) preparing the prepared silicon-carbon negative electrode material: carboxymethyl cellulose (CMC): styrene Butadiene Rubber (SBR): SP conductive carbon black (SP) is prepared by mixing 70: 10: 10: 10, mixing, preparing the mixture into slurry by using 1-methyl-2-pyrrolidone (NMP), uniformly coating the slurry on a copper foil, and carrying out vacuum drying at 80 ℃ for 24 hours to obtain the experimental battery pole piece. Then using a lithium plate as a counter electrode and using 1.1mol/L LiPF6The four-component mixed solvent is prepared according to Ethylene Carbonate (EC): dimethyl carbonate (DMC): vinylene Carbonate (VC): fluoroethylene carbonate (FEC) ═ 1: 1: 1: 1, adopting a polypropylene microporous membrane as a diaphragm, assembling into a CR2025 button half cell in a vacuum glove box, discharging to 5mV at a constant current of 0.1 ℃, then discharging to 5mV at a constant current of 0.02 ℃, and charging to 1.5V at a constant current of 0.1 ℃.
Example 2
The embodiment provides a preparation method of a silicon-carbon negative electrode material of a lithium ion battery, which specifically comprises the following steps:
a: weighing 5g of nano silicon with the median particle size of 100nm and 10g of natural graphite, placing the nano silicon and the natural graphite in a 500mL beaker, stirring and mixing the nano silicon and the natural graphite for 10min, and placing the mixture in a ball milling tank for ball milling for 2 hours at the rotating speed of 300 r/min;
b: adding 1.5g of asphalt into 25g of tetrahydrofuran and mixing;
c: adding the mixed solution obtained in the step B into the ball milling tank in the step A;
d: adding 0.05g of CMC to the mixture obtained in step C and ball milling the mixture for 3 hours;
e: d, placing the mixture obtained in the step D in an oven at the temperature of 70 ℃ for drying for 12 hours until the organic solvent is completely volatilized;
f: crushing the mixture obtained in the step E and sieving the crushed mixture with a 300-mesh sieve;
g: and F, placing the mixture obtained in the step F in a box-type carbonization furnace, introducing nitrogen as protective gas at the flow rate of 80L/h for 2.5 hours, then starting to heat up at the heating rate of 3 ℃/min to 1000 ℃, preserving heat for 4 hours, and naturally cooling to obtain the silicon-carbon negative electrode material for the lithium ion battery.
And (3) preparing the prepared silicon-carbon negative electrode material: CMC: SBR: SP comprises the following components in percentage by mass of 70: 10: 10: 10, mixing, preparing the mixture into slurry by using NMP, uniformly coating the slurry on a copper foil, and carrying out vacuum drying at 80 ℃ for 24 hours to obtain the experimental battery pole piece. Then using a lithium plate as a counter electrode and using 1.1mol/L LiPF6The four-component mixed solvent is as follows: DMC: VC: FEC 1: 1: 1: 1, adopting a polypropylene microporous membrane as a diaphragm, assembling into a CR2025 button half cell in a vacuum glove box, discharging to 5mV at a constant current of 0.1 ℃, then discharging to 5mV at a constant current of 0.02 ℃, and charging to 1.5V at a constant current of 0.1 ℃.
Example 3
The embodiment provides a preparation method of a silicon-carbon negative electrode material of a lithium ion battery, which specifically comprises the following steps:
a: weighing 5g of nano silicon with the median particle size of 30nm and 10g of artificial graphite, placing the nano silicon and the artificial graphite in a 500mL beaker, stirring and mixing the mixture for 10min, and placing the mixture in a ball milling tank for ball milling for 2 hours at the rotating speed of 300 r/min;
b: adding 1.5g of asphalt into 25g of tetrahydrofuran and mixing;
c: adding the mixed solution obtained in the step B into the ball milling tank in the step A;
d: adding 0.05g of CMC to the mixture obtained in step C and ball milling the mixture for 3 hours;
e: d, placing the mixture obtained in the step D in an oven at the temperature of 80 ℃ for drying for 12 hours until the organic solvent is completely volatilized;
f: crushing the mixture obtained in the step E and sieving the crushed mixture with a 300-mesh sieve;
g: and F, placing the mixture obtained in the step F in a box-type carbonization furnace, introducing nitrogen as protective gas at the flow rate of 80L/h for 2.5 hours, then starting to heat up at the heating rate of 3 ℃/min to 1000 ℃, preserving heat for 4 hours, and naturally cooling to obtain the silicon-carbon negative electrode material for the lithium ion battery.
And (3) preparing the prepared silicon-carbon negative electrode material: CMC: SBR: SP comprises the following components in percentage by mass of 70: 10: 10: 10, mixing, preparing the mixture into slurry by using NMP, uniformly coating the slurry on a copper foil, and carrying out vacuum drying at 80 ℃ for 24 hours to obtain the experimental battery pole piece. Then using a lithium plate as a counter electrode and using 1.1mol/L LiPF6The four-component mixed solvent is as follows: DMC: VC: FEC 1: 1: 1: 1, adopting a polypropylene microporous membrane as a diaphragm, assembling into a CR2025 button half cell in a vacuum glove box, discharging to 5mV at a constant current of 0.1 ℃, then discharging to 5mV at a constant current of 0.02 ℃, and charging to 1.5V at a constant current of 0.1 ℃.
Example 4
The embodiment provides a preparation method of a silicon-carbon negative electrode material of a lithium ion battery, which specifically comprises the following steps:
a: weighing 5g of nano silicon with the median particle size of 40nm and 10g of natural graphite, placing the nano silicon and the natural graphite in a 500mL beaker, stirring and mixing the mixture for 10min, and placing the mixture in a ball milling tank for ball milling for 2 hours at the rotating speed of 300 r/min;
b: adding 1.5g of asphalt into 25g of tetrahydrofuran and mixing;
c: adding the mixed solution obtained in the step B into the ball milling tank in the step A;
d: adding 0.05g of CMC to the mixture obtained in step C and ball milling the mixture for 3 hours;
e: d, placing the mixture obtained in the step D in an oven at the temperature of 60-80 ℃ for drying for 12 hours until the organic solvent is completely volatilized;
f: crushing the mixture obtained in the step E and sieving the crushed mixture with a 300-mesh sieve;
g: and F, placing the mixture obtained in the step F in a box-type carbonization furnace, introducing nitrogen as protective gas at the flow rate of 80L/h for 2.5 hours, then starting to heat up at the heating rate of 3 ℃/min to 1000 ℃, preserving heat for 4 hours, and naturally cooling to obtain the silicon-carbon negative electrode material for the lithium ion battery.
And (3) preparing the prepared silicon-carbon negative electrode material: CMC: SBR: SP comprises the following components in percentage by mass of 70: 10: 10: 10, mixing, preparing the mixture into slurry by using NMP, uniformly coating the slurry on a copper foil, and carrying out vacuum drying at 80 ℃ for 24 hours to obtain the experimental battery pole piece. Then using a lithium plate as a counter electrode and using 1.1mol/L LiPF6The four-component mixed solvent is as follows: DMC: VC: FEC 1: 1: 1: 1, adopting a polypropylene microporous membrane as a diaphragm, assembling into a CR2025 button half cell in a vacuum glove box, discharging to 5mV at a constant current of 0.1 ℃, then discharging to 5mV at a constant current of 0.02 ℃, and charging to 1.5V at a constant current of 0.1 ℃.
Example 5
The embodiment provides a preparation method of a silicon-carbon negative electrode material of a lithium ion battery, which specifically comprises the following steps:
a: weighing 5g of nano silicon with the median particle size of 100nm and 15g of artificial graphite, placing the nano silicon and the artificial graphite in a 500mL beaker, stirring and mixing the mixture for 10min, and placing the mixture in a ball milling tank for ball milling for 2 hours at the rotating speed of 300 r/min;
b: adding 1.5g of asphalt into 25g of tetrahydrofuran and mixing;
c: adding the mixed solution obtained in the step B into the ball milling tank in the step A;
d: adding 0.05g of CMC to the mixture obtained in step C and ball milling the mixture for 3 hours;
e: d, placing the mixture obtained in the step D in an oven at the temperature of 80 ℃ for drying for 12 hours until the organic solvent is completely volatilized;
f: crushing the mixture obtained in the step E and sieving the crushed mixture with a 300-mesh sieve;
g: and F, placing the mixture obtained in the step F in a box-type carbonization furnace, introducing nitrogen as protective gas at the flow rate of 80L/h for 2.5 hours, then starting to heat up at the heating rate of 3 ℃/min to 1000 ℃, preserving heat for 4 hours, and naturally cooling to obtain the silicon-carbon negative electrode material for the lithium ion battery.
And (3) preparing the prepared silicon-carbon negative electrode material: CMC: SBR: SP comprises the following components in percentage by mass of 70: 10: 10: 10, mixing, preparing the mixture into slurry by using NMP, uniformly coating the slurry on a copper foil, and carrying out vacuum drying at 80 ℃ for 24 hours to obtain the experimental battery pole piece. Then using a lithium plate as a counter electrode and using 1.1mol/L LiPF6The four-component mixed solvent is as follows: DMC: VC: FEC 1: 1: 1: 1, adopting a polypropylene microporous membrane as a diaphragm, assembling into a CR2025 button half cell in a vacuum glove box, discharging to 5mV at a constant current of 0.1 ℃, then discharging to 5mV at a constant current of 0.02 ℃, and charging to 1.5V at a constant current of 0.1 ℃.
Example 6
The embodiment provides a preparation method of a silicon-carbon negative electrode material of a lithium ion battery, which specifically comprises the following steps:
a: weighing 5g of nano silicon with the median particle size of 100nm and 15g of artificial graphite, placing the nano silicon and the artificial graphite in a 500mL beaker, stirring and mixing the mixture for 10min, and placing the mixture in a ball milling tank for ball milling for 2 hours at the rotating speed of 300 r/min;
b: adding 1.5g of asphalt into 20g of tetrahydrofuran and mixing;
c: adding the mixed solution obtained in the step B into the ball milling tank in the step A;
d: adding 0.05g of CMC to the mixture obtained in step C and ball milling the mixture for 3 hours;
e: d, placing the mixture obtained in the step D in an oven at the temperature of 70 ℃ for drying for 12 hours until the organic solvent is completely volatilized;
f: crushing the mixture obtained in the step E and sieving the crushed mixture with a 300-mesh sieve;
g: and F, placing the mixture obtained in the step F in a box-type carbonization furnace, introducing nitrogen as protective gas at the flow rate of 80L/h for 2.5 hours, then starting to heat up at the heating rate of 3 ℃/min to 1000 ℃, preserving heat for 4 hours, and naturally cooling to obtain the silicon-carbon negative electrode material for the lithium ion battery.
And (3) preparing the prepared silicon-carbon negative electrode material: CMC: SBR: SP comprises the following components in percentage by mass of 70: 10: 10: 10, mixing, preparing the mixture into slurry by using NMP, uniformly coating the slurry on a copper foil, and carrying out vacuum drying at 80 ℃ for 24 hours to obtain the experimental battery pole piece. Then using a lithium plate as a counter electrode and using 1.1mol/L LiPF6The four-component mixed solvent is as follows: DMC: VC: FEC 1: 1: 1: 1, adopting a polypropylene microporous membrane as a diaphragm, assembling into a CR2025 button half cell in a vacuum glove box, discharging to 5mV at a constant current of 0.1 ℃, then discharging to 5mV at a constant current of 0.02 ℃, and charging to 1.5V at a constant current of 0.1 ℃.
Example 7
The embodiment provides a preparation method of a silicon-carbon negative electrode material of a lithium ion battery, which specifically comprises the following steps:
a: weighing 5g of nano silicon with the median particle size of 100nm and 15g of natural graphite, placing the nano silicon and the natural graphite in a 500mL beaker, stirring and mixing the mixture for 10min, and placing the mixture in a ball milling tank for ball milling for 2 hours at the rotating speed of 300 r/min;
b: adding 1.5g of asphalt into 20g of tetrahydrofuran and mixing;
c: adding the mixed solution obtained in the step B into the ball milling tank obtained in the step A;
d: adding 0.05g of CMC to the mixture from step C and ball milling the mixture for 3 hours;
e: putting the mixture obtained in the step D into an oven at the temperature of 60 ℃ for drying for 12 hours until the organic solvent is completely volatilized;
f: crushing the mixture obtained in the step E and sieving the crushed mixture with a 300-mesh sieve;
g: and F, placing the mixture obtained in the step F in a box-type carbonization furnace, introducing nitrogen as protective gas at the flow rate of 80L/h for 2.5 hours, then starting to heat up at the heating rate of 3 ℃/min to 1000 ℃, preserving heat for 4 hours, and naturally cooling to obtain the silicon-carbon negative electrode material for the lithium ion battery.
And (3) preparing the prepared silicon-carbon negative electrode material: CMC: SBR: SP comprises the following components in percentage by mass of 70: 10: 10: 10, mixing, preparing the mixture into slurry by using NMP, uniformly coating the slurry on a copper foil, and carrying out vacuum drying at 80 ℃ for 24 hours to obtain the experimental battery pole piece. Then using a lithium plate as a counter electrode and using 1.1mol/L LiPF6The four-component mixed solvent is as follows: DMC: VC: FEC 1: 1: 1: 1, adopting a polypropylene microporous membrane as a diaphragm, assembling into a CR2025 button half cell in a vacuum glove box, discharging to 5mV at a constant current of 0.1 ℃, then discharging to 5mV at a constant current of 0.02 ℃, and charging to 1.5V at a constant current of 0.1 ℃.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (9)

1. A method for preparing a silicon-carbon negative electrode material of a lithium battery is characterized by comprising the following steps:
mixing nano-silicon and graphite with a median particle size of 3-15 um according to a mass ratio of 5: 10-10: 30, and putting the mixture into a ball milling tank for ball milling for 1-3 hours;
mixing asphalt and tetrahydrofuran according to the mass ratio of 3: 50-3: 40 to form an asphalt mixed solution, and adding the asphalt mixed solution into a ball milling tank for ball milling to form a first mixture; in the first mixture, the mass ratio of the asphalt mixed solution to the silicon to the graphite is 20:5: 10-40: 10: 30;
adding carboxymethyl cellulose (CMC) accounting for 1-5% of the mass of silicon into the first mixture, and mixing and ball-milling for 3-5 hours to obtain a second mixture;
drying the second mixture in an oven for 8-12 hours to ensure that all organic solvents in the second mixture are volatilized to obtain a third mixture;
crushing and screening the third mixture;
placing the sieved substances in a box-type carbonization furnace, and introducing nitrogen at the flow rate of 50-80L/h; and (3) heating up 2.5-5 hours after nitrogen is introduced, heating up to 900-1000 ℃ after 4-6 hours, preserving heat for 2-4 hours, and naturally cooling to obtain the silicon-carbon cathode material of the lithium ion battery.
2. The method for preparing the silicon-carbon anode material for the lithium battery as claimed in claim 1, wherein the ball milling tank is an agate ball milling tank with a volume of 100mL, zirconium dioxide zirconium beads with a purity of 95% are used in the ball milling tank, and the amount of the zirconium beads accounts for 1/3 of the volume of the ball milling tank.
3. The method for preparing the silicon-carbon anode material of the lithium battery as claimed in claim 1, wherein the graphite has a median particle size of 6-12 um.
4. The method for preparing the silicon-carbon anode material of the lithium battery as claimed in claim 3, wherein the graphite has a median particle size of 8-11 um.
5. The method for preparing the silicon-carbon anode material of the lithium battery as claimed in claim 1, wherein the temperature of the oven is 60-80 ℃.
6. The method for preparing the silicon-carbon anode material of the lithium battery as claimed in claim 1, wherein the mixing of the pitch and the tetrahydrofuran is performed in a beaker and stirred with a glass stirring rod.
7. The method for preparing the silicon-carbon anode material of the lithium battery as claimed in claim 1, wherein the sieving is a 300-mesh sieve.
8. A silicon carbon negative electrode material for lithium batteries, prepared by the method of any one of claims 1 to 7.
9. A lithium battery comprising the lithium battery silicon carbon negative electrode material as claimed in claim 8.
CN201911025032.6A 2019-10-25 2019-10-25 Method for preparing silicon-carbon negative electrode material of lithium battery, negative electrode material and lithium battery Pending CN110723721A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111342035A (en) * 2020-03-11 2020-06-26 西安越遴新材料研究院有限公司 Method for modifying silicon-carbon composite negative electrode by asphalt modification process derivative
CN114792801A (en) * 2022-03-29 2022-07-26 海安智川电池材料科技有限公司 Novel battery cathode material and preparation method thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140302394A1 (en) * 2013-04-03 2014-10-09 Shenzhen Btr New Energy Materials Inc Lithium ion battery graphite negative electrode material and preparation method thereof
CN106257716A (en) * 2016-08-30 2016-12-28 浙江超威创元实业有限公司 The preparation method of a kind of silicon-carbon composite cathode material and lithium ion battery
CN108963208A (en) * 2018-06-22 2018-12-07 清华大学深圳研究生院 A kind of preparation method and lithium ion battery of silicon-carbon cathode material
CN109755517A (en) * 2018-12-29 2019-05-14 陕西煤业化工技术研究院有限责任公司 A kind of silicon-carbon composite anode material for lithium ion battery and preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140302394A1 (en) * 2013-04-03 2014-10-09 Shenzhen Btr New Energy Materials Inc Lithium ion battery graphite negative electrode material and preparation method thereof
CN106257716A (en) * 2016-08-30 2016-12-28 浙江超威创元实业有限公司 The preparation method of a kind of silicon-carbon composite cathode material and lithium ion battery
CN108963208A (en) * 2018-06-22 2018-12-07 清华大学深圳研究生院 A kind of preparation method and lithium ion battery of silicon-carbon cathode material
CN109755517A (en) * 2018-12-29 2019-05-14 陕西煤业化工技术研究院有限责任公司 A kind of silicon-carbon composite anode material for lithium ion battery and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
中国硅酸盐学会: "《矿物材料学科发展报告 2016-2017》", 31 March 2018, 北京：中国科学技术出版社 *
邓凌峰等: ""包覆天然石墨作锂离子电池负极材料的研究"", 《电池工业》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111342035A (en) * 2020-03-11 2020-06-26 西安越遴新材料研究院有限公司 Method for modifying silicon-carbon composite negative electrode by asphalt modification process derivative
CN114792801A (en) * 2022-03-29 2022-07-26 海安智川电池材料科技有限公司 Novel battery cathode material and preparation method thereof

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